diff options
Diffstat (limited to 'drivers/leds/leds-is31fl32xx.c')
| -rw-r--r-- | drivers/leds/leds-is31fl32xx.c | 504 |
1 files changed, 504 insertions, 0 deletions
diff --git a/drivers/leds/leds-is31fl32xx.c b/drivers/leds/leds-is31fl32xx.c new file mode 100644 index 000000000000..9a6785694886 --- /dev/null +++ b/drivers/leds/leds-is31fl32xx.c @@ -0,0 +1,504 @@ +/* + * Driver for ISSI IS31FL32xx family of I2C LED controllers + * + * Copyright 2015 Allworx Corp. + * + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Datasheets: http://www.issi.com/US/product-analog-fxled-driver.shtml + */ + +#include <linux/device.h> +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> + +/* Used to indicate a device has no such register */ +#define IS31FL32XX_REG_NONE 0xFF + +/* Software Shutdown bit in Shutdown Register */ +#define IS31FL32XX_SHUTDOWN_SSD_ENABLE 0 +#define IS31FL32XX_SHUTDOWN_SSD_DISABLE BIT(0) + +/* IS31FL3216 has a number of unique registers */ +#define IS31FL3216_CONFIG_REG 0x00 +#define IS31FL3216_LIGHTING_EFFECT_REG 0x03 +#define IS31FL3216_CHANNEL_CONFIG_REG 0x04 + +/* Software Shutdown bit in 3216 Config Register */ +#define IS31FL3216_CONFIG_SSD_ENABLE BIT(7) +#define IS31FL3216_CONFIG_SSD_DISABLE 0 + +struct is31fl32xx_priv; +struct is31fl32xx_led_data { + struct led_classdev cdev; + u8 channel; /* 1-based, max priv->cdef->channels */ + struct is31fl32xx_priv *priv; +}; + +struct is31fl32xx_priv { + const struct is31fl32xx_chipdef *cdef; + struct i2c_client *client; + unsigned int num_leds; + struct is31fl32xx_led_data leds[0]; +}; + +/** + * struct is31fl32xx_chipdef - chip-specific attributes + * @channels : Number of LED channels + * @shutdown_reg : address of Shutdown register (optional) + * @pwm_update_reg : address of PWM Update register + * @global_control_reg : address of Global Control register (optional) + * @reset_reg : address of Reset register (optional) + * @pwm_register_base : address of first PWM register + * @pwm_registers_reversed: : true if PWM registers count down instead of up + * @led_control_register_base : address of first LED control register (optional) + * @enable_bits_per_led_control_register: number of LEDs enable bits in each + * @reset_func: : pointer to reset function + * + * For all optional register addresses, the sentinel value %IS31FL32XX_REG_NONE + * indicates that this chip has no such register. + * + * If non-NULL, @reset_func will be called during probing to set all + * necessary registers to a known initialization state. This is needed + * for chips that do not have a @reset_reg. + * + * @enable_bits_per_led_control_register must be >=1 if + * @led_control_register_base != %IS31FL32XX_REG_NONE. + */ +struct is31fl32xx_chipdef { + u8 channels; + u8 shutdown_reg; + u8 pwm_update_reg; + u8 global_control_reg; + u8 reset_reg; + u8 pwm_register_base; + bool pwm_registers_reversed; + u8 led_control_register_base; + u8 enable_bits_per_led_control_register; + int (*reset_func)(struct is31fl32xx_priv *priv); + int (*sw_shutdown_func)(struct is31fl32xx_priv *priv, bool enable); +}; + +static const struct is31fl32xx_chipdef is31fl3236_cdef = { + .channels = 36, + .shutdown_reg = 0x00, + .pwm_update_reg = 0x25, + .global_control_reg = 0x4a, + .reset_reg = 0x4f, + .pwm_register_base = 0x01, + .led_control_register_base = 0x26, + .enable_bits_per_led_control_register = 1, +}; + +static const struct is31fl32xx_chipdef is31fl3235_cdef = { + .channels = 28, + .shutdown_reg = 0x00, + .pwm_update_reg = 0x25, + .global_control_reg = 0x4a, + .reset_reg = 0x4f, + .pwm_register_base = 0x05, + .led_control_register_base = 0x2a, + .enable_bits_per_led_control_register = 1, +}; + +static const struct is31fl32xx_chipdef is31fl3218_cdef = { + .channels = 18, + .shutdown_reg = 0x00, + .pwm_update_reg = 0x16, + .global_control_reg = IS31FL32XX_REG_NONE, + .reset_reg = 0x17, + .pwm_register_base = 0x01, + .led_control_register_base = 0x13, + .enable_bits_per_led_control_register = 6, +}; + +static int is31fl3216_reset(struct is31fl32xx_priv *priv); +static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv, + bool enable); +static const struct is31fl32xx_chipdef is31fl3216_cdef = { + .channels = 16, + .shutdown_reg = IS31FL32XX_REG_NONE, + .pwm_update_reg = 0xB0, + .global_control_reg = IS31FL32XX_REG_NONE, + .reset_reg = IS31FL32XX_REG_NONE, + .pwm_register_base = 0x10, + .pwm_registers_reversed = true, + .led_control_register_base = 0x01, + .enable_bits_per_led_control_register = 8, + .reset_func = is31fl3216_reset, + .sw_shutdown_func = is31fl3216_software_shutdown, +}; + +static int is31fl32xx_write(struct is31fl32xx_priv *priv, u8 reg, u8 val) +{ + int ret; + + dev_dbg(&priv->client->dev, "writing register 0x%02X=0x%02X", reg, val); + + ret = i2c_smbus_write_byte_data(priv->client, reg, val); + if (ret) { + dev_err(&priv->client->dev, + "register write to 0x%02X failed (error %d)", + reg, ret); + } + return ret; +} + +/* + * Custom reset function for IS31FL3216 because it does not have a RESET + * register the way that the other IS31FL32xx chips do. We don't bother + * writing the GPIO and animation registers, because the registers we + * do write ensure those will have no effect. + */ +static int is31fl3216_reset(struct is31fl32xx_priv *priv) +{ + unsigned int i; + int ret; + + ret = is31fl32xx_write(priv, IS31FL3216_CONFIG_REG, + IS31FL3216_CONFIG_SSD_ENABLE); + if (ret) + return ret; + for (i = 0; i < priv->cdef->channels; i++) { + ret = is31fl32xx_write(priv, priv->cdef->pwm_register_base+i, + 0x00); + if (ret) + return ret; + } + ret = is31fl32xx_write(priv, priv->cdef->pwm_update_reg, 0); + if (ret) + return ret; + ret = is31fl32xx_write(priv, IS31FL3216_LIGHTING_EFFECT_REG, 0x00); + if (ret) + return ret; + ret = is31fl32xx_write(priv, IS31FL3216_CHANNEL_CONFIG_REG, 0x00); + if (ret) + return ret; + + return 0; +} + +/* + * Custom Software-Shutdown function for IS31FL3216 because it does not have + * a SHUTDOWN register the way that the other IS31FL32xx chips do. + * We don't bother doing a read/modify/write on the CONFIG register because + * we only ever use a value of '0' for the other fields in that register. + */ +static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv, + bool enable) +{ + u8 value = enable ? IS31FL3216_CONFIG_SSD_ENABLE : + IS31FL3216_CONFIG_SSD_DISABLE; + + return is31fl32xx_write(priv, IS31FL3216_CONFIG_REG, value); +} + +/* + * NOTE: A mutex is not needed in this function because: + * - All referenced data is read-only after probe() + * - The I2C core has a mutex on to protect the bus + * - There are no read/modify/write operations + * - Intervening operations between the write of the PWM register + * and the Update register are harmless. + * + * Example: + * PWM_REG_1 write 16 + * UPDATE_REG write 0 + * PWM_REG_2 write 128 + * UPDATE_REG write 0 + * vs: + * PWM_REG_1 write 16 + * PWM_REG_2 write 128 + * UPDATE_REG write 0 + * UPDATE_REG write 0 + * are equivalent. Poking the Update register merely applies all PWM + * register writes up to that point. + */ +static int is31fl32xx_brightness_set(struct led_classdev *led_cdev, + enum led_brightness brightness) +{ + const struct is31fl32xx_led_data *led_data = + container_of(led_cdev, struct is31fl32xx_led_data, cdev); + const struct is31fl32xx_chipdef *cdef = led_data->priv->cdef; + u8 pwm_register_offset; + int ret; + + dev_dbg(led_cdev->dev, "%s: %d\n", __func__, brightness); + + /* NOTE: led_data->channel is 1-based */ + if (cdef->pwm_registers_reversed) + pwm_register_offset = cdef->channels - led_data->channel; + else + pwm_register_offset = led_data->channel - 1; + + ret = is31fl32xx_write(led_data->priv, + cdef->pwm_register_base + pwm_register_offset, + brightness); + if (ret) + return ret; + + return is31fl32xx_write(led_data->priv, cdef->pwm_update_reg, 0); +} + +static int is31fl32xx_reset_regs(struct is31fl32xx_priv *priv) +{ + const struct is31fl32xx_chipdef *cdef = priv->cdef; + int ret; + + if (cdef->reset_reg != IS31FL32XX_REG_NONE) { + ret = is31fl32xx_write(priv, cdef->reset_reg, 0); + if (ret) + return ret; + } + + if (cdef->reset_func) + return cdef->reset_func(priv); + + return 0; +} + +static int is31fl32xx_software_shutdown(struct is31fl32xx_priv *priv, + bool enable) +{ + const struct is31fl32xx_chipdef *cdef = priv->cdef; + int ret; + + if (cdef->shutdown_reg != IS31FL32XX_REG_NONE) { + u8 value = enable ? IS31FL32XX_SHUTDOWN_SSD_ENABLE : + IS31FL32XX_SHUTDOWN_SSD_DISABLE; + ret = is31fl32xx_write(priv, cdef->shutdown_reg, value); + if (ret) + return ret; + } + + if (cdef->sw_shutdown_func) + return cdef->sw_shutdown_func(priv, enable); + + return 0; +} + +static int is31fl32xx_init_regs(struct is31fl32xx_priv *priv) +{ + const struct is31fl32xx_chipdef *cdef = priv->cdef; + int ret; + + ret = is31fl32xx_reset_regs(priv); + if (ret) + return ret; + + /* + * Set enable bit for all channels. + * We will control state with PWM registers alone. + */ + if (cdef->led_control_register_base != IS31FL32XX_REG_NONE) { + u8 value = + GENMASK(cdef->enable_bits_per_led_control_register-1, 0); + u8 num_regs = cdef->channels / + cdef->enable_bits_per_led_control_register; + int i; + + for (i = 0; i < num_regs; i++) { + ret = is31fl32xx_write(priv, + cdef->led_control_register_base+i, + value); + if (ret) + return ret; + } + } + + ret = is31fl32xx_software_shutdown(priv, false); + if (ret) + return ret; + + if (cdef->global_control_reg != IS31FL32XX_REG_NONE) { + ret = is31fl32xx_write(priv, cdef->global_control_reg, 0x00); + if (ret) + return ret; + } + + return 0; +} + +static inline size_t sizeof_is31fl32xx_priv(int num_leds) +{ + return sizeof(struct is31fl32xx_priv) + + (sizeof(struct is31fl32xx_led_data) * num_leds); +} + +static int is31fl32xx_parse_child_dt(const struct device *dev, + const struct device_node *child, + struct is31fl32xx_led_data *led_data) +{ + struct led_classdev *cdev = &led_data->cdev; + int ret = 0; + u32 reg; + + if (of_property_read_string(child, "label", &cdev->name)) + cdev->name = child->name; + + ret = of_property_read_u32(child, "reg", ®); + if (ret || reg < 1 || reg > led_data->priv->cdef->channels) { + dev_err(dev, + "Child node %s does not have a valid reg property\n", + child->full_name); + return -EINVAL; + } + led_data->channel = reg; + + of_property_read_string(child, "linux,default-trigger", + &cdev->default_trigger); + + cdev->brightness_set_blocking = is31fl32xx_brightness_set; + + return 0; +} + +static struct is31fl32xx_led_data *is31fl32xx_find_led_data( + struct is31fl32xx_priv *priv, + u8 channel) +{ + size_t i; + + for (i = 0; i < priv->num_leds; i++) { + if (priv->leds[i].channel == channel) + return &priv->leds[i]; + } + + return NULL; +} + +static int is31fl32xx_parse_dt(struct device *dev, + struct is31fl32xx_priv *priv) +{ + struct device_node *child; + int ret = 0; + + for_each_child_of_node(dev->of_node, child) { + struct is31fl32xx_led_data *led_data = + &priv->leds[priv->num_leds]; + const struct is31fl32xx_led_data *other_led_data; + + led_data->priv = priv; + + ret = is31fl32xx_parse_child_dt(dev, child, led_data); + if (ret) + goto err; + + /* Detect if channel is already in use by another child */ + other_led_data = is31fl32xx_find_led_data(priv, + led_data->channel); + if (other_led_data) { + dev_err(dev, + "%s and %s both attempting to use channel %d\n", + led_data->cdev.name, + other_led_data->cdev.name, + led_data->channel); + goto err; + } + + ret = devm_led_classdev_register(dev, &led_data->cdev); + if (ret) { + dev_err(dev, "failed to register PWM led for %s: %d\n", + led_data->cdev.name, ret); + goto err; + } + + priv->num_leds++; + } + + return 0; + +err: + of_node_put(child); + return ret; +} + +static const struct of_device_id of_is31fl31xx_match[] = { + { .compatible = "issi,is31fl3236", .data = &is31fl3236_cdef, }, + { .compatible = "issi,is31fl3235", .data = &is31fl3235_cdef, }, + { .compatible = "issi,is31fl3218", .data = &is31fl3218_cdef, }, + { .compatible = "issi,is31fl3216", .data = &is31fl3216_cdef, }, + {}, +}; + +MODULE_DEVICE_TABLE(of, of_is31fl31xx_match); + +static int is31fl32xx_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + const struct is31fl32xx_chipdef *cdef; + const struct of_device_id *of_dev_id; + struct device *dev = &client->dev; + struct is31fl32xx_priv *priv; + int count; + int ret = 0; + + of_dev_id = of_match_device(of_is31fl31xx_match, dev); + if (!of_dev_id) + return -EINVAL; + + cdef = of_dev_id->data; + + count = of_get_child_count(dev->of_node); + if (!count) + return -EINVAL; + + priv = devm_kzalloc(dev, sizeof_is31fl32xx_priv(count), + GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->client = client; + priv->cdef = cdef; + i2c_set_clientdata(client, priv); + + ret = is31fl32xx_init_regs(priv); + if (ret) + return ret; + + ret = is31fl32xx_parse_dt(dev, priv); + if (ret) + return ret; + + return 0; +} + +static int is31fl32xx_remove(struct i2c_client *client) +{ + struct is31fl32xx_priv *priv = i2c_get_clientdata(client); + + return is31fl32xx_reset_regs(priv); +} + +/* + * i2c-core requires that id_table be non-NULL, even though + * it is not used for DeviceTree based instantiation. + */ +static const struct i2c_device_id is31fl31xx_id[] = { + {}, +}; + +MODULE_DEVICE_TABLE(i2c, is31fl31xx_id); + +static struct i2c_driver is31fl32xx_driver = { + .driver = { + .name = "is31fl32xx", + .of_match_table = of_is31fl31xx_match, + }, + .probe = is31fl32xx_probe, + .remove = is31fl32xx_remove, + .id_table = is31fl31xx_id, +}; + +module_i2c_driver(is31fl32xx_driver); + +MODULE_AUTHOR("David Rivshin <drivshin@allworx.com>"); +MODULE_DESCRIPTION("ISSI IS31FL32xx LED driver"); +MODULE_LICENSE("GPL v2"); |